Second twin.  [electronic resource] 

 -  British medical journal  Jun 1968 
 - 641 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0007-1447 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Birth Order<br/>Birth Weight<br/>Female<br/>Humans<br/>Infant Mortality<br/>Infant, Newborn<br/>Male<br/>Pregnancy<br/>Twins